Drum assembly for washing machine

ABSTRACT

A lifter is provided on a drum for lifting and dropping laundry in the drum during a rotation of the drum. The lifter slides and moves along an inner surface of the drum after passing through the inner surface so as to be engaged to the drum. At least one slot is provided on a circumference of the drum, and at least one hook is provided on the lifter for being engaged to the slot. Further, at least one projection is provided on the drum, and at least on rib is provided on the lifter. The projection and the rib are tightly engaged with each other so as to secure the lifter to the drum when the lifter completely slides and moves laterally.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Utility Model Application No. U2004-013533, filed on May 15, 2004, which is hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a washing machine, and more particularly, to a drum assembly with lifters therein for lifting and dropping laundry to improve washing, rinsing, and dehydrating performances.

2. Discussion of the Related Art

Washing machine is a representative home appliance for washing laundry using detergent and water. The washing machine is generally classified into two types, i.e., a top loading type and a front loading type based on the location of an opening for receiving the laundry.

The top loading type washing machine generally comprises a vertical tub for accommodating the laundry, a pulsater rotating in the tub and washing the laundry, and a lid provided on an upper surface of the washing machine for opening and closing the tub.

The front loading type washing machine generally comprises a horizontal tub for accommodating washing water, a horizontal drum provided in the tub for accommodating the laundry, at least one lifter provided on an inner surface of the drum for lifting and dropping the laundry when the drum is rotated for washing, rinsing or dehydrating the laundry, and a door provided on a front surface of the washing machine for opening and closing the drum.

As mentioned above, there is at least one lifter in the drum of the front loading type washing machine. And, the lifter is generally mounted on an inner surface of the drum by coupling members such as screws or bolts. Thus, there are disadvantages in the above mentioned coupling structure of the drum and the lifter that it takes long time for an assembler to fix the lifters to the drum and that the assembling process for producing the washing machine become complicated.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a drum assembly for washing machine that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to improve a structure of a drum assembly of the washing machine so that an assembler can fix lifters to a drum quickly and easily.

Another object of the present invention is to improve the structure of the drum assembly of the washing machine so that lifters are stably secured to the drum.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a drum assembly for washing machine comprises a drum accommodating laundry therein, and at least one lifter provided on an inner surface of the drum, and lifting and dropping the laundry in the drum during a rotation of the drum, wherein the lifter slides on the inner surface of the drum after passing through a circumference of the drum so as to be engaged with the drum.

The drum may comprise a cylinder including a space accommodating the laundry therein, a back mounted on a rear of the cylinder, and a front cover mounted on a front of the cylinder and having an opening which is opened and closed by a door.

The drum may further comprise at least one slot provided on the circumference of the drum. And, the lifter may comprise at least one hook put into the slot and moving along a longitudinal direction of the slot so as to be engaged with the slot when the lifter slides. The slot may be configured to be elongated along a longitudinal direction of the drum. The slot may be configured to hold a head of the hook after the head passes through the slot and laterally moves along the longitudinal direction of the slot.

The hook may comprise a neck extended from the lifter, and a head formed on an end of the neck. And, the slot may comprise a wide portion allowing the head to pass through therein and a narrow portion narrower than the head and connected to the wide portion for receiving the neck when the lifter slides on the inner surface of the drum.

The slot of the drum may further comprise at least one rounded portion provided between the wide portion and the narrow portion, and smoothly guiding the hook put into the wide portion into the narrow portion. Wherein, the rounded portion is provided on both sides of the narrow portion, or is provided on one side of the narrow portion.

The slot may comprise a pair of slots arranged to have a predetermined distance therebetween. The pair of slots may be configured to be formed that the hook put into each slot is bent with elasticity when the lifter is secured to the drum. And, the pair of slots may be configured to be getting far away from each other along a sliding direction of the lifter. Further, each slot of the pair of slots may comprise an end accommodating each hook when the lifter is secured to the drum, wherein a distance between the each end is longer than a distance between the each hook.

The drum may further comprise a projection extended from the drum and supporting the lifter so as to prevent the lifter from sliding backward after the lifter is secured to the drum. The lifter may be configured to go over the projection when the lifter slides on the inner surface of the drum so as to be secured to the drum. Wherein, the projection comprises a slope provided on an upper surface of the projection so that the lifter smoothly goes over the projection along on the slope when the lifter slides so as to be coupled to the drum.

The drum may further comprise a cut away portion surrounding a portion of the projection, further wherein the projection is configured to be formed that the portion of the projection surrounding the cut away portion is bent toward an inside the drum. The projection is configured to be bent with a predetermined slope.

The lifter may further comprise a protrusion extended from the lifter, wherein the protrusion is engaged with the projection so as to prevent the lifter from sliding backward after the lifter is secured to the drum.

The lifter in the drum may further comprise a recess provided on a lower portion of the lifter; and a rib provided on the recess and reinforcing strength of the lifter, wherein the rib is engaged with the projection and secures the lifter to the drum when the lifter is coupled to the drum.

The drum may further comprise at least one projection extended from the drum between the pair of slots, wherein the projection supports the lifter so as to prevent the lifter from sliding backward after the lifter is secured to the drum.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment of the invention and together with the description serve to explain the principle of the invention. In the drawings;

FIG. 1 illustrates a cross sectional view of the washing machine according to the present invention;

FIG. 2 illustrates an exploded perspective view of the drum assembly according to the present invention;

FIG. 3 illustrates a perspective view of the assembled drum assembly according to the present invention; and

FIG. 4 illustrates a perspective view of the other embodiment of slots formed in the drum according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

With reference to FIG. 1, a case 1 of the washing machine according to the present invention comprises a base plate 2, a wall 4, a top cover 6, and a front cover 8. The base plate 2 forms a bottom of the case 2, and the wall 4 is vertically mounted on the base plate 2, and forms a rear wall and both side walls of the washing machine according to the present invention. A top of the wall 4 is open, and a front of the wall is also open. And, the top cover 6 covers the open top of the wall 4, and the front cover 8 covers the open front of the wall 4. Further, there is a control panel 12 between a top of the front cover 8 and the top cover 6 so that the user can control the washing machine using the control panel 12.

There is a horizontal tub 14 in the case 1 for holding washing water therein. The tub 14 is suspended in the case 1 by a plurality of springs 5 and dampers 3. The springs 5 are provided between an upper portion of the tub 14 and the case 1, and the dampers 3 are provided between a lower portion of the tub 14 and the case 1. The springs 5 and the dampers 3 not only suspend the tub 14 in the case 1, but also reduce the vibration of the tub 14 generated during the operation of the washing machine.

There is an opening 16 on a front portion of the tub 14, and there is an opening 9 on the front cover 8 of the case 1. The openings 9 and 16 communicate with each other and face each other. And, a door 10 coupled to the front cover 8 of the case 1 by a hinge opens and closes the openings 9 and 16. Further, there is a gasket 22 between the opening 16 of the tub 14 and the door 10. The gasket 22 prevents a leakage of the washing water stored in the tub 14.

There is a water supply hole 18 on the upper portion of the tub 14 for supplying the washing water into the tub 14. The water supply hole 18 communicates with a water supply hose 60 through a detergent box 65. Thus, the washing water is supplied into the tub 14 with detergent stored in the detergent box 65. And, there is a drain 20 for draining the washing water in the tub 14 on the lower portion of the tub 14. The drain 20 communicates with a drain hose 70 through a drain pump 75. Thus, contaminated washing water in the tub 14 is drained out through the drain 20 and the drain hose 70 when the drain pump 75 is operated.

There is a rotatable and horizontal drum assembly 40 for accommodating laundry therein in the tub 14. The drum assembly is directly driven by a motor 20 mounted on a rear surface of the tub 14. The motor 24 comprises a stator 26 fixed to the rear surface of the tub 14, and a rotatable rotor 28 surrounding the stator 28. A spider 30 is mounted on a rear surface of the drum assembly 40, and a shaft 33 connected to the rotor 28 is connected to the spider 30 through the tub 14.

The drum assembly 40 according to the present invention comprises a drum 100 accommodating the laundry therein, and at least one lifter 200 provided on an inner surface of the drum 100. The lifter 200 lifts and drops the laundry in the drum 100 during a rotation of the drum 100 in order to improve washing, rinsing, and dehydrating performances of the washing machine. FIGS. 2 and 3 illustrate the structure of the drum assembly 40 according to the present invention in detail. Thus, detailed structure of the drum assembly 40 will be described in the followings with reference to FIGS. 2 and 3.

The drum 100 comprises a cylinder 110, a back 120, and a front cover 130. The cylinder 110 forms a circumference of the drum 100 and has a space for accommodating the laundry therein. The back 120 is mounted on an open rear of the cylinder 110 and covers the rear of the cylinder 110. The front cover 130 is mounted on an open front of the cylinder 110, and covers the front of the cylinder 110.

There are a plurality of apertures 115 on the circumference of the drum 100, i.e., the cylinder 110 and the back 120, as shown in FIGS. 1 and 2. Thus, the washing water in the tub 14 can be introduced into the space of the drum 100 through the apertures 115. In addition, there is an opening 131 on the front cover 130, so the user can put the laundry into the drum 100 and can draw the laundry in the drum 100 outward through the opening 131. The opening 131 is opened and closed by the door 10. Further, the spider 30 is mounted on a rear surface of the back 120, as shown in FIG. 1.

As mentioned above, in the conventional washing machine, lifters are mounted on a drum by coupling members such as screws. On the contrary, in the washing machine according to the present invention, the lifter 200 is engaged with and secured to the drum 100 without any separate coupling members such as screws or bolts. More particularly, the lifter 200 according to the present invention has a portion passing through the inner surface of the drum 100 and sliding along the inner surface of the drum 100 when the lifter is coupled to the drum 100. Thereby, the lifter 200 can be engaged with and secured to the drum 100 without any coupling members such as screws and bolts. Such unique coupling structure of the drum 100 and the lifter 200 according to the present invention will be described in the followings in detail.

As shown in FIG. 2, there is at least one slot 150 on the circumference of the drum 100, i.e., the cylinder 110. The slot 150, for example, is elongated along a longitudinal direction of the drum 100. The slot 150 has a pair of slots having a predetermined distance therebetween. Each slot of the pair of slots is arranged to be approximately parallel to each other as shown in FIG. 2. Each pair of slots is arranged to be along the longitudinal direction of the drum 100, and to be apart from one another with a predetermined distance. And, a plurality of rows of slots is provided along the circumference of the drum 100 as shown in FIGS. 2 and 3.

The lifter 200 comprises at least one hook 210, and each hook 210 is engaged to each slot 150. The hook 210 is extended from a lower portion of the lifter 200, and slides and moves along a longitudinal direction of the slot 150 after being put into the slot 150. Thereby, the hook 210 of the lifter 200 is engaged to and secured to the slot 150 of the drum 100. The hook 210 comprises a neck 211 extended from the lower portion of the lifter 200, and a head 215 formed on an end of the neck 211. Wherein the head 215, for example, has a wedge shape with a sharp tip as shown in FIG. 2, and has a width wider than a width of the neck 211.

After being putting into and passing through the slot 150, the head 215 moves along the longitudinal direction of the slot 150 as the lifter 200 slides and moves laterally so as to be coupled to the drum 100. After that, the head 215 is held by a portion of the slot 150 in where the hook 210 is finally accommodated, and can not be released from the portion the slot 150. Thereby the lifter 200 as well as the hook 210 is engaged to and secured to the drum 200.

For this, the slot 150, for example, comprises a wide portion 151 having a wide width, and a narrow portion 155 connected to the wide portion 151. The wide portion 151 is wide enough to allow the head 215 to pass through therein, and the narrow portion 155 is narrower than the wide portion 151. Wherein, the narrow portion 155 is wide enough to receive the neck 211 of the hook 210 when the lifter 200 slides and moves along the longitudinal direction of the slot 150, but is narrower than the width of the head 215. In other words, the narrow portion 155 is narrow enough to prevent the head 215 from passing through therein.

There are stepped portions between the wide portion 151 and the narrow portion 155. And there is at least one rounded portion 160 on the stepped portion. The rounded portion 160 guides the hook 210, especially the neck 211 in the wide portion 151 into the narrow portion 155 smoothly. The rounded portion 160 can be provided on each stepped portion on both sides of the narrow portion 155 as shown in FIG. 2. On the contrary, the rounded portion 160 also can be provided on only one stepped portion on one side of the narrow portion 155 as shown in FIG. 4.

Meanwhile, it is preferable that the hook 210 is engaged to the drum 100 with elasticity rather than that the hook 210 is engaged to the drum 100 with no elasticity. Then, the lifter 200 can be more stably mounted on the drum 100 without any play. Therefore, it is preferable that the pair of slots 150 is formed that each hook 210 can be bent with elasticity when the lifter 200 is completely secured to the drum 200.

For this, the pair of slots 150 arranged to have the predetermined distance therebetween is formed that the pair of slots 150 are getting far away from each other along a sliding direction of the lifter 200 rather than that the pair of slots 150 are arranged to exactly parallel to each other, as shown in FIG. 4. In other words, the predetermined distance between the pair of slots 150 is getting longer along the sliding direction of the lifter 200. Thus, while a distance between each wide portion 151 of the pair of slots 150 is substantially the same as a distance ‘h’ between each hook 210, a distance ‘H’ between each narrow portion 155 of the pair of slots 150 is greater than the distance ‘h’ between each hook 210.

In this case, each neck 211 of the pair of hooks 210 is getting more bent outward as the pair of hooks 210 slides and moves along the longitudinal direction of the slot 150 after the pair of hooks 210 being put into a pair of slots 150. Therefore, the pair of necks 211 of the pair of hooks 210 tightly grasps a portion of the drum 100 between each slot 150 of the pair of slots 150 as shown in FIG. 3. Thereby the lifter 200 is stably secured to the drum 100 when the hook 210 is completely inserted into the narrow portion 155 of the slot 150 due to the elasticity of the hook 210.

Meanwhile, there is a projection 170 on the drum 100 for preventing the lifter 200 completely secured to the drum 100 from being released from the drum 100. The projection 170 is extended from the inner surface of the drum 100 to an inside the drum 100 as shown in FIG. 2. The projection 170 supports the lifter 200 in order to prevent the lifter 200 from sliding backward after the lifter 200 is completely coupled to the drum 100. Thereby, a release of the lifter 200 from the drum 100 is effectively prevented. Further detailed structure of the projection 170 provided on the drum 100 will be described in the followings with reference to FIG. 3.

As shown in FIG. 3, there is at least one cut away portion 180 on the circumference of the drum 100, wherein the cut away portion 180 surrounds a portion of the drum 100. The cut away portion 180, for example, has a U-shape, and the portion of the drum 100 surrounded by the cut away portion 180 is bent toward the inside the drum 100 with a predetermined slop. Thereby, the bent portion forms the projection 170. As mentioned above, the projection 170 is tilted and thereby the projection 170 has a slope on an upper surface thereof which is connected to the inner surface of the drum 100. Meanwhile, the projection 170, for example, is disposed between the pair of slots 150, as shown in FIGS. 2 and 3.

There is at least one protrusion provided on the lifter 200, the protrusion is engaged with the projection 170 when the lifter 200 is secured to the drum 100. More particularly, the protrusion, for example, is provided on a lower surface of the lifter 200, and is engaged with the projection 170 in order to secure the lifter 200 to the drum 100 when the lifter 200 is completely coupled to the drum 100.

Meanwhile, there is a recess 220 provided on the lower portion of the lifter 200 for reducing the weight of the lifter 200, and there is at least one rib 230 provided on the recess 220 for reinforcing the strength of the lifter 200. Thus, it is preferable that the rib 230 is engaged with the projection 170 when the lifter 200 is engaged to the drum 100 so as to play a role as the protrusion mentioned above, as shown in FIG. 2, rather than that the protrusion is provided on the lower surface of the lift 200 separate from the rib 230 so as to be engaged to the drum 100.

An assembling process of the drum 100 and the lifter 200 will be described in the followings in detail. Above all, the assembler puts each hook 210 into each wide portion 151 of each slot 150, then the head 215 of the hook 210 passes through the wide portion 151 of the slot 150. After that, the assembler laterally pushes the lifter 200 along the longitudinal direction of the slot 150, then the neck 211 accommodated in the wide portion 151 is transferred into the narrow portion 155 of the slot 150. At this time, the rounded portion 160 smoothly guides the neck 211 in the wide portion 151 into the narrow portion 155.

As the neck 211 of the hook 200 comes into the narrow portion 155, the neck 211 of the hook 200 is getting more bent outward with the elasticity. In addition, as the lifter 200 slides and moves laterally along the longitudinal direction of the slot 150, the rib 230 protruded from on the recess 200 smoothly goes over the slope on the upper portion of the bent and tilt projection 170. At this time, the bent projection 170 is pushed toward the outside of the drum 100 with elasticity by the rib 230.

Finally, the rib 230 completely passes over the projection 170 when the lifter 200 is completely moved laterally. Then, the projection 170 pushed by the rib 230 is returned to the initial location by the elasticity, and thereby the projection 170 is tightly engaged with a side of the rib 230 and supports the rib 230. Therefore, the lifter 200 can not slide backward, and thereby the lifter 200 is stably secured to the drum 100 with no play.

As mentioned above, the lifter according to the present invention is secured to the drum without any separable coupling members such as screws or bolts. Thus, the assembler can assemble the drum assembly quickly and with ease. In addition, since a pair of hook tightly grasps the portion of the drum between two slots with elasticity and the projection of the drum is tightly engaged with the rib of the lifter, the lifter is stably secured to the drum with no play.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

1. A drum assembly for washing machine comprising: a drum accommodating laundry therein; and at least one lifter provided on an inner surface of the drum, and lifting and dropping the laundry in the drum during a rotation of the drum, wherein the lifter slides on the inner surface of the drum after passing through a circumference of the drum so as to be engaged with the drum.
 2. The drum assembly as claimed in claim 1, wherein the drum comprises a cylinder including a space accommodating the laundry therein; a back mounted on a rear of the cylinder; and a front cover mounted on a front of the cylinder, and having an opening which is opened and closed by a door.
 3. The drum assembly as claimed in claim 1, wherein the drum comprises at least one slot provided on the circumference of the drum, and the lifter comprises at least one hook put into the slot and moving along a longitudinal direction of the slot so as to be engaged with the slot when the lifter slides.
 4. The drum assembly as claimed in claim 3, wherein the slot is configured to be elongated along a longitudinal direction of the drum.
 5. The drum assembly as claimed in claim 3, wherein the slot is configured to hold a head of the hook after the head passes through the slot and laterally moves along the longitudinal direction of the slot.
 6. The drum assembly as claimed in claim 1, wherein the lifter comprises a hook including a neck extended from the lifter and a head formed on an end of the neck, and the drum comprises a slot including a wide portion allowing the head to pass through therein and a narrow portion narrower than the head and connected to the wide portion for receiving the neck when the lifter slides on the inner surface of the drum.
 7. The drum assembly as claimed in claim 6, wherein the slot further comprises at least one rounded portion provided between the wide portion and the narrow portion, and smoothly guiding the hook put into the wide portion into the narrow portion.
 8. The drum assembly as claimed in claim 7, wherein the rounded portion is provided on both sides of the narrow portion.
 9. The drum assembly as claimed in claim 7, wherein the rounded portion is provided on one side of the narrow portion.
 10. The drum assembly as claimed in claim 3, wherein the slot comprises a pair of slots arranged to have a predetermined distance therebetween.
 11. The drum assembly as claimed in claim 10, wherein the pair of slots is configured to be formed that the hook put into each slot is bent with elasticity when the lifter is secured to the drum.
 12. The drum assembly as claimed in claim 10, wherein the pair of slots is configured to be getting far away from each other along a sliding direction of the lifter.
 13. The drum assembly as claimed in claim 10, wherein each slot of the pair of slots includes an end accommodating each hook when the lifter is secured to the drum, further wherein a distance between the each end is longer than a distance between the each hook.
 14. The drum assembly as claimed in claim 1, wherein the drum comprises a projection extended from the drum and supporting the lifter so as to prevent the lifter from sliding backward after the lifter is secured to the drum.
 15. The drum assembly as claimed in claim 14, wherein the lifter is configured to go over the projection when the lifter slides on the inner surface of the drum so as to be secured to the drum.
 16. The drum assembly as claimed in claim 14, wherein the projection comprises a slope provided on an upper surface of the projection so that the lifter smoothly goes over the projection along on the slope when the lifter slides so as to be coupled to the drum.
 17. The drum assembly as claimed in claim 14, wherein the drum comprises a cut away portion surrounding a portion of the projection, further wherein the projection is configured to be formed that the portion of the projection surrounding the cut away portion is bent toward an inside the drum.
 18. The drum assembly as claimed in claim 17, wherein the projection is configured to be bent with a predetermined slope.
 19. The drum assembly as claimed in claim 14, wherein the lifter comprises a protrusion extended from the lifter, wherein the protrusion is engaged with the projection so as to prevent the lifter from sliding backward after the lifter is secured to the drum.
 20. The drum assembly as claimed in claim 14, wherein the lifter comprises a recess provided on a lower portion of the lifter; and a rib provided on the recess and reinforcing strength of the lifter, wherein the rib is engaged with the projection and secures the lifter to the drum when the lifter is coupled to the drum.
 21. The drum assembly as claimed in claim 10, wherein the drum further comprises at least one projection extended from the drum between the pair of slots, wherein the projection supports the lifter so as to prevent the lifter from sliding backward after the lifter is secured to the drum. 